16
SUPPLY AND RETURN LINES
Determine the configuration of the supply and return
lines from the outdoor furnace to where the supply and
return lines will connect to the existing heating system.
Central Boiler recommends using the ThermoPEX
®
piping system.
ThermoPEX is a fully assembled, pre-insulated
piping system consisting of two 1" Central PEX lines
or two 1-1/4" PEX lines. The two lines (one a supply
and one a return line) are insulated with high-density
urethane insulation and a thick, durable, waterproof,
polyethylene outer jacket. One of the lines is marked
with a black stripe for identification.
NOTE: To prevent ground water from entering the
house, do not use drain tile, PVC pipe with bubble
wrap, or any other inferior material for insulating
the water lines.
NOTE: If the outdoor furnace supply and return
lines are not insulated properly, or if other
brands of insulated piping are used, there can be
excessive heat loss. This heat loss can greatly
increase the fuel consumption.
NOTE: If it is unavoidable that the supply and
return lines will run through an area of ponding
water, use ThermoPEX instead of other materials.
ThermoPEX should also be used for above-
ground or winter installations, and if the area is
likely to be affected by compaction.
Above Ground or Winter Installations
For above ground or winter installations in which
the supply and return lines can not immediately be
buried underground, Central Boiler recommends using
ThermoPEX. Be sure that both the insulation and the
supply and return lines will not be exposed to ultraviolet
rays. The ThermoPEX black exterior jacket has UV
protection but the insulation and water lines inside do
not. Use a ThermoPEX termination cap at each end of
the installation to protect and seal the insulation from
water.
If installed next to the building being heated, the supply
and return lines can be installed above ground provided
they are properly insulated and not exposed to ultraviolet
rays (see Fig. 17 as an example).
Fig. 17
For illustration only. Actual configurations will vary.
Existing
Forced Air
Furnace
NOTE: If an above ground installation is
temporary, bury the ThermoPEX as soon as
conditions permit (e.g., once the ground has
thawed).
NOTE: If ThermoPEX is installed temporarily
above ground, provisions should be made (i.e.,
a firestop) to prevent possible risk of fire coming
into contact with the ThermoPEX. ThermoPEX
is constructed of materials that can burn and
transfer a fire.
CAUTION
If ThermoPEX is installed temporarily above
ground, do not cover with combustible materials
(e.g., stray, hay, leaves, etc.).
SECTION 6 – SYSTEM INSTALLATION
Section 6 - System Installation
